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The Frontier of New Physics - Pearl Sandick
The Standard Model of
While regular matter makes up about one-sixth of the
from the Big Bang that we can observe today,” said Sandick.
particle physics is the theory
total matter in the universe, dark matter makes up five-sixths.
that explains how the most
There are compelling arguments that dark matter might
and composition of the universe, including how much is made
elementary particles interact
actually be a new type of elementary particle. Electrons
of dark matter. The CMB also can provide hints about what
with each other and combine
are an example of an elementary particle—they are the
other particles or objects existed in the early universe.”
most fundamental building blocks of their type and are not
composed of other particles. Other examples of elementary
hot and very dense. In this environment, the densest
over the course of many decades, what we know as the
particles include quarks, neutrinos, and photons.
places would have collapsed to become black holes. The
Standard Model today was formulated nearly half a century
black holes that formed in this way are called primordial
ago and remains a focus of study for particle physicists. But by
workshop entitled “The Search for New Physics—Leaving No
black holes (PBHs), to differentiate them from black holes
itself, the Standard Model fails to provide an explanation for
Stone Unturned,” which brought together dozens of particle
that form much later when stars reach the end of their
many important phenomena, such as the existence of the dark
physicists, astrophysicists, and cosmologists from around
lives. Heavy enough PBHs would still be around today and
matter in the universe.
the world to discuss recent advances and big ideas. “It was
could make up some or all of the dark matter, providing an
such a vibrant environment; I think it helped us all broaden
alternative to the idea that dark matter is a new particle.
the search for physics beyond the Standard Model, using
our perspectives and learn new things. Though there’s a lot
Lighter PBHs probably are not an explanation for dark
connections between theoretical particle physics, cosmology,
going on in the meantime, we’re already excited about
matter, but they would have had an important interplay
and astrophysics to help us understand the universe.
the prospect of hosting a second “No Stone Unturned”
with dark matter and other new particles.
workshop in the new Science Building.”
Astronomy and Associate Dean of Faculty Affairs for the
Barmak Shams Es Haghi, have been looking into the many
College of Science, is on that frontier. As a theoretical particle
cosmological phenomenon—black holes—tackling the
impacts of a population of light PBHs in the early universe.
physicist, she studies some of the largest and smallest
question of how their existence affects our understanding of
Recently, they’ve completed the first precision study of
things in the universe, including dark matter, which is
dark matter and other physics beyond the Standard Model.
some spinning PBHs in the early universe, finding that
the mysterious stuff that gravitationally binds galaxies and
current CMB measurements from the Planck satellite (an
clusters of galaxies together.
microwave background (CMB), which is leftover radiation
to form composite objects, like protons and neutrons. Developed
12
Today, physicists and researchers are on the frontier in
Pearl Sandick, Associate Professor of Physics and
In August 2019, Sandick and her colleagues hosted a
Recently, Sandick has turned her attention to another
“Some of this new research makes use of the cosmic
“CMB measurements can help us understand the structure
Before the CMB was created, the universe was very
Sandick, along with a U of U postdoctoral associate,
observatory operated by the European Space Agency) and
